Extractor for drawing presses



Dec. l0, 1968 o. BIGINELLI EXTRACTOR FOR DRAWING PRESSES Filed Oct. 18. 1965 United States Patent O 7 claims. (l. 72-290) ABSTRACT OF THE DISCLOSURE The Ipresent disclosure relates generally to drawing presses and more particularly to an improved extractor for such presses. The press provided with the extractor according to the invention comprises a drawing die and a drawing .piston received in a tubular element to be drawn. This piston is movable axially to draw the tubular element. The extractor comprises a stop spaced from the die and has an opening aligned with the piston. A retractor is provided comprising a body of revolution having a `stem portion and integral heads at opposite ends of the stem portion. A first one of the heads is seated on the end of the piston and is to`o large to pass through an opening in the bottom of the tubular element. The second of the heads is small enough to pass through the opening in the bottom of the tubular element and through the opening in the stop plate. The second head passes through the plate opening when the tubular element is fully drawn. A movable locking fork slides under the second head of the retractor element and is `supported by the stop plate to immobilize the retractor element and thereby hold the drawn tubular element while the piston is withdrawn from the tubular element.

A first object of the invention is to produce a drawing press for tubular elements of. slight thickness and great length.

Another object of the invention is to produce, after each drawing pass, while the tubular element being drawn extends and its thickness diminishes, the extraction of the drawn element held on the press piston, and this without distorting the walls of the drawn element.

Other objects and advantages of the invention will be understood as described in the following speciiication and appended claims, as well as the attached figure illustrating a fragmentary longitudinal section view of a press provided with an extractor according to the invention.

According to the invention, the extractor device, more particularly usable for a tubular element drawn which is drawn on a press, consists of an extractor member 1, inserted in the partially open bottom of a cup or tubular element 2 to be drawn. The extractor member consists of a revolving body comprising at each end 11 and 12, conical or cylindro-conical parts opposed having their bases so as to form small collars for bearing, on the one hand, on the internal border of the partially open bottom 21 of the tubular element to be drawn and on the other, on the external face of a locking fork 3, for holding the extractor member against a stop plate 4 during the withdrawal of the piston 5 after drawing of the element.

The end parts 11 and 12 of the extractor member are of dierent diameters more particularly the head part 11 which has a smaller diameter than the part 12 so as to lbe able to pass through the opening provided in the bottom of the tubular element 2.

The head 12 of the extractor member is held on the piston head by means of a conical centering stem portion provided on the piston head and also by the bottom 21 of the tubular element, bearing on the base of the small collar of the head 12 of the extractor member.

3,415,099 Patented Dec. 10, 1968 ice The head 11 of the extractor member has a smaller diameter than that of the head 12 so as to be able to pass through the opening in the bottom of the tubular element 2, so that the projecting part can penetrate through the opening made in the stop plate 4.

The stop plate 4 is attached to the frame of the press by means of columns 7 erected in the extension of the drawing die 6. As the piston moves upwardly with the tubular element thereon the element is drawn in the die 6. The piston is shown in phantom in the position in which it finishes its stroke and the extractor removes the drawn element therefrom.

The columns 7 are so dimensioned as to allow the whole of the length of the drawn tubular element to pass, and thus enable the withdrawal of the piston when the tubular element is completely drawn, which remains fixed to the stop plate 4 by means of the locking fork 3 locking the extractor member 1 by bearing, on the one hand, on the external faces of the stop plate, and on the other, by the small collar formed by the head 11 of the extractor member. The tubular element is thus securely anchored to the stop plate and the withdrawal of the piston 1 can be easily elTected without damaging the tubular element, even when the latter has a very great length and very thin walls.

After withdrawing the piston, the extractor member is released from the stop plate by removing the mobile fork 3.

The head 11 of the extractor member can then pass` through the opening of the stop plate, enabling the drawnout tubular elem'ent to be withdrawn from the guide 8 which is integral with the stop plate 4.

The extractor member is provided with an internal channel 13 affording communication Awith the outer air in the direction of the press piston 1, thus facilitating the withdrawal of the piston due to balanced pressures.

Of course, the invention is not restricted to the examples of embodiment described and shown above; thus, for example, the extraction member can be made under any other form of embodiment of the locking fork, being mechanized or otherwise, for fitting on the stop plate of the press; the press can, without any inconvenience, be of the vertical or horizontal type.

What I claim is:

1. In combination with a press for drawing a tubular element having a central 'opening in its bottom, said press having a drawing die and a drawing piston received in said tubular element and movable axially relative to said die to draw said tubular element; means for extracting a drawn tubular element from said piston, 'comprising a stop plate spaced from said die and having an opening aligned with said piston, means supporting said stop plate in fixed position relative to said die, a retractor element comprising a body of revolution having a stem portion and integral heads at opposite ends of said stem portion, a rst one of said heads being seated on the end of said piston and being of a size too large to pass through said opening in the bottom of said tubular element and the second of said heads being small enough to pass through said opening in the Ibottom of said tubular element and through the opening in said stop plate, `said stop plate being positioned so that said second head of said extractor element passes through said opening in said stop plate when said tubular element is fully drawn, and a movable locking fork slidable under said second head of said retractor element and supported by said stop plate to immobilize said retractor element and thereby hold said drawn tubular element while said piston is withdrawn from said tubular element.

2. Apparatus according to claim 1, in which said stop plate is supported by a plurality of columns extending l`between said stop plate and a support for said die.

3. Apparatus according to claim 2, in which a tubular guide extends between said die and stop plate to receive said tubular element.

4. Apparatus according to claim 1, in which said retractor element has an axial extending channel providing communication `between the atmosphere and the space between the end of said piston and the bottom of said tubular element to avoid drawing a vac-uum in said space as said piston is withdrawn.

5. Apparatus according to claim 1, in which said heads of said retractor element are generally frusto-conical.

6. Apparatus according to claim 5, in which the end of said piston is provided with a recess in which said first head of said retractor element seats.

7. Apparatus according to claim 6, in which said first head of said retractor element has a diameter smaller than the diameter of said piston.

References Cited UNITED STATES PATENTS 616,357 12/1898 Reynolds et al 72-283 0 RICHARD J. HERBST, Primary Examiner. 

